1. Field of the Invention
This invention relates to data set maintenance on a mainframe computer system comprising a catalog directory structure and more particularly relates to automating volume table of contents (VTOC) driven data set maintenance.
2. Description of the Related Art
In dynamically reusable software environments, such as test environments, automated test cases reconfigure and reinitialize the contents of a direct access storage device (DASD). Data sets which have been allocated for prior test cases are removed en masse to make space for data sets required by new tests. A given test case or process does not necessarily know which test case preceded it, and does not necessarily know what the prior contents of the DASD were. Consequently, various programs are used to scratch the entire contents of a volume using a VTOC parameter, which specifies that all data sets on an indicated volume, with a few specific exceptions, are to be scratched. While this process eliminates the necessity to know the specific contents of a volume before removing them, it does not remove the entries for the scratched data sets in the various integrated catalog facility (ICF) catalogs that reference the scratched data sets.
Consequently, catalogs may reference data sets which no longer exist. If subsequent steps in the process try to access a data set which no longer exists, or try to validate the existence of the data set, the catalog entry which no longer reflects the actual status of the data set will cause unexpected results or errors. Consequently, automated tests may fail resulting in allocation failures, duplicate data set name errors, and a loss of productivity.
Presently, a maintenance operation to remove data sets allocated to a prior test case is categorized as SCRATCH VTOC type DASD maintenance because it uses the VTOC parameter of a maintenance utility to scratch the contents of the DASD. As a result of this type of maintenance, several ill favored situations can arise. For example, a data set may have an entry in an ICF catalog but no longer exist on a volume. Another example might be that a virtual storage access method (VSAM) cluster may be cataloged but the DATA or INDEX data set associated with the VSAM cluster may no longer exist on a volume. Yet another example that might occur due to maintenance, but not SCRATCH VTOC type DASD maintenance, might be that the data set exists on a volume but no longer has an entry in an ICF catalog. There are no current solutions that will prevent these problems and others from arising due to maintaining dynamically-reusable environments. Current solutions are only aimed at remedying the problems that arise due to maintenance, therefore, they can be characterized as after-the-fact remedies.
For example, one such remedy utilizes a program with a parameter to handle cataloging issues in order to fix data set problems. Similarly, another program used as an after-the-fact remedy includes a parameter for fixing VSAM cluster problems. Although these programs are capable of remedying most ICF catalog issues that arise after maintenance, they require substantial input from a user, who must spend time analyzing an error situation, to be capable of remedying that error situation. These programs can be used by themselves or in combination to remedy data set problems and VSAM cluster problems resulting from data set maintenance. Unfortunately, they consume valuable time and resources after the maintenance which leads to the problem.
Other programs are available to fix catalog problems after-the-fact. One such program is IBM's Integrated Catalog Forward Recovery Utility (ICFRU). ICFRU is a basic tool to help in a forward recovery situation. ICFRU does not offer a wide range of features, but can help for catalog recovery. Because it is a limited program, it is only beneficial under certain circumstances. One circumstance might be where the problem arises due to a data set reportedly being cataloged but not actually existing. Consequently, it would not be able to remedy all problems occurring due to data set maintenance, such as when the data set exists and is supposed to be cataloged, but is not.
Still other programs are capable of recovering a catalog after a disaster. Although these programs have increased the speed at which problems occurring due to maintenance are fixed, they are not capable of preventing those problems from occurring. Thus, they are a round-a-bout after-the-fact way of dealing with errors due to data set maintenance. A more efficient approach would be to prevent the errors from occurring, which would eliminate the need for after-the-fact remedies.
Due to the foregoing, a need exists for an apparatus, system, and method that would prevent problems from occurring due to a SCRATCH VTOC-type DASD maintenance such as a data set having an entry in an ICF catalog but no longer existing on a volume, a VSAM cluster being cataloged but the DATA or INDEX data set associated with the VSAM cluster no longer existing on a volume, or a data set existing on a volume but no longer having an entry in an ICF catalog. Beneficially, such an apparatus, system, and method would automate VTOC driven data set maintenance.